Persisting Prefabs across scenes

I have created a SoundManager that persists across scenes so that the music is not interrupted. I have also created an object pool so that if a user were to click an in-game element multiple times the sound overlaps rather than cuts off the previous sounds.

I have implemented the object pooling manager as described in the Unity lesson (https://unity3d.com/learn/tutorials/topics/scripting/object-pooling) which works fine when staying and only used in a scene but the trouble I am having is persisting the prefabs collection from across scenes.

On startup I instantiate the SoundManager, load the sounds and then create the object pool. The object pool is created and populated with the prefab audiosource to create the channels I require. This is all working fine but when I transition to the game scene the soundmanager has persisted but collection list has null object in the new scene:

SoundManager

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class SoundManager : MonoBehaviour 
 {
     public AudioSource musicSource, uiSFXSource;
 
     private List<string> _clips;
 
     public static bool MusicLoaded { get; private set; }
 
     public static SoundManager Instance { get; private set; }
 
     private ObjectPoolingManager _gamePool;
 
     // Use this for initialization
     void Awake () 
     {
         // First we check if there are any other instances conflicting
         if(Instance != null && Instance != this)
         {
             // If that is the case, we destroy other instances
             Destroy(gameObject);
             return;
         }
         
         // Here we save our singleton instance
         Instance = this;
 
         MusicLoaded = false;
 
         InitClips();
 
         InitMusic();
 
         InitPool();
 
         // Furthermore we make sure that we don't destroy between scenes (this is optional)
         DontDestroyOnLoad(gameObject);
     }
 
     private void InitMusic()
     {
         MusicLoaded = false;
         AudioClip music = Resources.Load("Audio/MusicFile") as AudioClip;
         music.LoadAudioData();
 
         StartCoroutine(MusicLoadStatus(music));
     }
 
     public void InitPool()
     {
         GameObject audioSource = Instantiate(Resources.Load("Prefabs/GameSFXAudioSource")) as GameObject;
         _gamePool = new ObjectPoolingManager();
         _gamePool.Init(audioSource);
     }
 
     IEnumerator MusicLoadStatus(AudioClip music)
     {
         while (music.loadState != AudioDataLoadState.Loaded) 
         {
             yield return null;
         }
 
         MusicLoaded = true;
         musicSource.clip = music;
         StartMusic();
     }
 
     private void InitClips()
     {
         
         _clips = new List<string>();
 
         _clips.Add("Clips1");
         _clips.Add("Clips2");
         _clips.Add("Clips3");
         _clips.Add("Clips4");
         _clips.Add("Clips5");
         _clips.Add("Clips6");
         _clips.Add("Clips7");
         _clips.Add("Clips8");
     }
 
     public void PlayTapSFX()
     {
         if(PlayerPreference.Instance.SFXOnOff)
         {
             uiSFXSource.Play();
         }
     }
 
     public void PlayGameTapSFX()
     {
         if(PlayerPreference.Instance.SFXOnOff)
         {
             string clipToUse = _clips[Random.Range(0, _clips.Count-1)];
 
             AudioClip clip = Resources.Load("Audio/SFX/" + clipToUse) as AudioClip;
 
             GameObject obj = _gamePool.GetPooledObject();
             obj.SetActive(true);
             AudioManager sfx = obj.GetComponent<AudioManager>();
             sfx.InitClip(clip);
         }
     }
 
     public void StartMusic()
     {
         if(PlayerPreference.Instance.MusicOnOff)
         {
             musicSource.Play();
         }
     }
 
     public void StopMusic()
     {
         musicSource.Stop();
     }
 
 }
 

ObjectPoolingManager

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class ObjectPoolingManager : MonoBehaviour 
 {
     private GameObject pooledObject;
     public int poolSize = 5;
     public bool willGrow = true;
 
     public List<GameObject> poolObjects;
 
     void Start () 
     {
         poolObjects = new List<GameObject>();
     }
 
     public void Init(GameObject _pooledObj)
     {
         
         pooledObject = _pooledObj;
 
         for (int i = 0; i < poolSize; i++) 
         {
             GameObject tempObj = (GameObject)Instantiate(pooledObject);
             tempObj.SetActive(false);
             poolObjects.Add(tempObj);
         }
     }
 
     public GameObject GetPooledObject()
     {
         for (int i = 0; i < poolObjects.Count; i++) 
         {
             if(!poolObjects[i].activeInHierarchy)
             {
                 return poolObjects[i];
             }
         }
 
         if(willGrow)
         {
             GameObject obj = Instantiate(pooledObject);
             obj.SetActive(false);
             poolObjects.Add(obj);
             return obj;
         }
 
         return null;
     }
 }
 

Is there a reason why the initialised prefab pooling collection doesn't persist across the scenes even though the collection has the same collection size across the scenes but the objects in it are null?